Construction members such as steel studs and door flames are made of different types of channels and frames which must be secured to other building members such as wall construction studs. This requires the use of many different types of fasteners. Doorways are made in wall construction by the use of pre-fabricated frames, such as steel channel frames which are fastened or anchored to wood or metal studs. Door frames are attached to wall studs with fastening or fastening devices by nails or screws. One type of anchor device is in the form of a box-shaped structure with a front wall and side walls and a size and shape that corresponds to an interior profile of a door frame member providing a door jamb. A plurality of frame fasteners are mounted on studs around the door frame, in order to anchor the door frame to form a door jamb. Door frame members are made in a large number of different sizes in which the width of the channels may vary. Different size fastening devices are needed to accommodate each specific door frame size. However, due to the many different types of building components such as door frames, this approach requires many different fastening devices, each of which require separate tooling and packaging, resulting in increased costs. Also, a separate inventory must be maintained for each specific fastening size, resulting in additional storage and other expenses.
In order to overcome these inefficiencies, adjustable frame fasteners have been devised. A two-piece fastener of this type is essentially formed of two half-pieces, each piece having a front wall and only a single side wall. The half-pieces are adjustably connected so that the end walls define the width to fit within a door frame member. The width of the anchor can be adjusted by varying the end-to-end spacing between the end walls. In this manner, the two-piece fastener design can be used with a range of door frame widths. However, this design requires two parts for each door frame fastener. This effectively doubles the expense of each door fastener, since double the material is required, along with doubling the manufacturing, inventory and shipping expenses and assembly. The majority of doorjamb applications are for only one standard size. Therefore, the two-piece fastener system is not the most economical for a large percentage of installations.